The adsorption and reaction of acetaldehyde on the clean and CO pre-covered Ru(0001) surfaces have been investigated using temperature programmed desorption method. On the clean Ru(0001) surface, the decomposition...
详细信息
The adsorption and reaction of acetaldehyde on the clean and CO pre-covered Ru(0001) surfaces have been investigated using temperature programmed desorption method. On the clean Ru(0001) surface, the decomposition of acetaldehyde is the main reaction channel, with little polymerization occurring. However, on the CO pre-covered Ru(0001) surface, the de- composition of acetaldehyde is inhibited considerably with increasing CO coverage. Whereas, the polymerization occurs efficiently, especially at high CO coverage (θco〉0.5 ML), which is strongly CO coverage dependent. Combined with previous studies, the well-ordered hexagohal structure of CO layer formed on the Ru(0001) surface at high CO coverage that matches the configuration of paraldehyde is likely to be the origin of this remarkable phenomenon.
Methanol/TiO2(110) is a model system in the surface science study of photocatalysis where methanol is taken as a hole capture. However, the highest occupied molecular orbital of adsorbed methanol lies below the vale...
详细信息
Methanol/TiO2(110) is a model system in the surface science study of photocatalysis where methanol is taken as a hole capture. However, the highest occupied molecular orbital of adsorbed methanol lies below the valence band maximum of TiO2, preventing the hole transfer. To study the level alignment of this system, electronic structure of methanol covered TiO2(110) surface has been measured by ultraviolet photoelectron spectroscopy and the molecular orbitals of adsorbed methanol have been clearly identified. The results indicate the weak interaction between methanol and TiO2 substrate. The static electronic structure also suggests the mismatch of the energy levels. These static experiments have been performed without band gap excitation which is the prerequisite of a photocatalytie process. Future study of the transient electronic structure using time-resolved UPS has also been discussed.
Covalent triazine-based frameworks(CTFs) are important microporous materials with a wide range of ***,we demonstrate an environmentally benign and economic synthetic pathway to *** monomers used for CTFs,aromatic ni...
详细信息
Covalent triazine-based frameworks(CTFs) are important microporous materials with a wide range of ***,we demonstrate an environmentally benign and economic synthetic pathway to *** monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate(Ⅱ) in place of commonly used toxic ***,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/*** the synthesized CTFs,CTF_(DCP) exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.
We study the H+CH4/CD4-+H2/HD+CH3/CD3 reactions using the time sliced velocity map ion imaging technique. Ion images of the CH3/CD3 products were measured by the (2+1) resonance enhanced multi-photon ionization ...
详细信息
We study the H+CH4/CD4-+H2/HD+CH3/CD3 reactions using the time sliced velocity map ion imaging technique. Ion images of the CH3/CD3 products were measured by the (2+1) resonance enhanced multi-photon ionization (REMPI) detection method. Besides the CH3/CD3 products in the ground state, ion images of the vibrationally excited CH3/CD3 products were also observed at two collision energies of 0.72 and 1.06 eV. It is shown that the angular distribution of the products CH3/CD3 in vibrationally excited states gradually vary from backward scattering to sideways scattering as the collision energy increases. Compared to the CH3/CD3 products in the ground state, the CH3/CD3 products in vibrationally excited states tend to be more sideways scattered, indicating that larger impact parameters play a more important role in the vibrationally excited product channels.
We report a new global and full-dimensional ground-state potential energy surface(PES)of the H+C2H4→H2+C2H3 *** PES was constructed by using fundamental invariant neural networks(FI-NN)fitting to about 100000 ab init...
详细信息
We report a new global and full-dimensional ground-state potential energy surface(PES)of the H+C2H4→H2+C2H3 *** PES was constructed by using fundamental invariant neural networks(FI-NN)fitting to about 100000 ab initio electronic energies calculated by the UCCSD(T)-F12a/aug-cc-pVTZ level of theory.
The exact short time propagator, in a form similar to the Crank-Nicholson method but in the spirit of spectrally transformed Hamiltonian, was proposed to solve the triatomic reactive time-dependent schrodinger equatio...
详细信息
The exact short time propagator, in a form similar to the Crank-Nicholson method but in the spirit of spectrally transformed Hamiltonian, was proposed to solve the triatomic reactive time-dependent schrodinger equation. This new propagator is exact and unconditionally convergent for calculating reactive scattering processes with large time step sizes. In order to improve the computational efficiency, the spectral difference method was applied. This resulted the Hamiltonian with elements confined in a narrow diagonal band. In contrast to our previous theoretical work, the discrete variable representation was applied and resulted in full Hamiltonian matrix. As examples, the collision energy-dependent probability of the triatomic H+H2 and O+O2 reaction are calculated. The numerical results demonstrate that this new propagator is numerically accurate and capable of propagating the wave packet with large time steps. However, the efficiency and accuracy of this new propagator strongly depend on the mathematical method for solving the involved linear equations and the choice of preconditioner.
暂无评论